^4 POLYAXDTJIA. POLIGYNIA. 



56, about the Icn.2;tl. of the calix. Utrkuli ob- 

 loiig, 6 to 9; 2-sce(!c(u 



An aquatic plant, with alternate, entire elliptic peltate 

 floating leaves, at first as v.'ell as the flowers and young- 

 er sho(;ts cnvel(;p,cd by a tenaceous and g'ellatinous fluid; 

 peduncles solitary, l-fio\vcrcd, flower brown. Styles 

 none. Stigma sin. pie, lateral, linear, on the iiiiK;r side 

 (almost similar to that of Sparganium). Seeds pcr.dulous 

 from the dorsal suture. 



Species. 1. R. peltata. Obs. Stfm, petiole, and pe- 

 duncle cyliiidric, covered witli an iuconspicuoi;s flcccu- 

 ler.t paL'Cscerce irr.mersed in a crellatinous substance, 

 which at first envelopes the youni;' leaves and Rowers. 

 Stem furnisiied will) 2 sets of confluent central vessels, 

 and also wi'h eAtenuil circle^ uf filiform tubes, tubes i"n 

 each circle 9 to 12; gant^-'-ons of central vessels about 4 

 in each set, each set sepai-nted by an empty tube; numer- 

 ous lonjjitudinal {)urp1e fibres y.re inlcrspersed with the 

 'exterior circle of tubes, appeurlnc^ at Icnjjtli to inoscu- 

 late on the underside of tlie leaf K'^i"R i^^ ^ purple colour, 

 as well as the stem, petiole,. peduncle, petais, stamina ancL 

 styles, there being notliinij in fact green in the whole 

 plant except the upper surface of the leaf. The central 

 vessels arrived in the leaf, from tlieir eccentrical/ and clou- 

 blc order, commiiuicate to it an eleu^ant and almost exactly 

 elliptic form, and finally resolve into about 12 nerves, la 

 tl>e peduncle there are 3 ganglions of centi-al vessels se- 

 pal ated from each other by inteirupted circles of aerial 

 tubes. — 5d. Obs. As the elliptic form of the leaf origin- 

 ates fj-om the eccentricity and duplicuturc of the central 

 vessels, expanding in an ellipse or 2 imci-secting circles, 

 so we onay justly consider it as a species of double leaf, 

 hence also "the ttumlna and the fruit is in the same man- 

 ner augmented. In its coordinate Cabombn which produ- 

 ces orbicular peltate leaves, v.e firvl only 6 stamina instead 

 of 18, 2 or 3 styles and capsules in place of 6 or more, but 

 comainitig ihe same number of seeds and of nearly the 

 same form. — Hence we perceive the same type in its sim- 

 ple form! A proof of the small importance of mere num- 

 ber in the character of classes or of natural groupes. 



There exists not the smnllest aitinity betwixt this very 

 singular plant and Caltha it is equally removed from eve- 

 ry other genus of the HANuxcuLACEi-E, ao<l its place in 

 the natural system has been well defined by the ingeni- 

 ous and indef 

 ir.t. 5. f, 22. 



